Tailoring interlayer magnetic coupling to modify the magnetic properties of FeCl2 bilayers by self-intercalation

Abstract

Manipulating the interlayer magnetic coupling of van der Waals magnetic materials is a feasible approach to modulate the magnetic properties, which is beneficial for the fundamental studies and practical applications in spintronics. Here, based on a systematic investigation of a FeCl₂ bilayer and its self-intercalated system, we propose that self-intercalation can effectively tune the interlayer magnetic coupling via the redistribution of interfacial charges. The interlayer magnetic exchange interaction transforms from the super–super-exchange to double-exchange, which results in ferromagnetic coupling between the neighboring van der Waals layers. Furthermore, the self-intercalated FeCl₂ bilayer shows half-metallic characteristics. More importantly, the magnetic anisotropy energy and Curie temperature of the self-intercalated FeCl₂ bilayer can be modulated by the intercalated concentration. These findings provide a promising route to engineer and manipulate the interlayer exchange mechanism and magnetic properties of the FeCl₂ bilayer and other van der Waals magnets.